"Four Posts on Ancient Poems" belongs to Kuangcao. It is characterized by being more wild than in the past, and the overall momentum is like the Yangtze River gushing thousands of miles, with strong winds and heavy rains, so it is a new breakthrough in the history of the development of cursive script. It breaks the restrained cursive style of the Wei and Jin Dynasties. The cursive script is based on the original basic structure, and the strokes of the upper and lower characters are closely connected. This is called "continuous and winding". Sometimes two characters look like one character, and sometimes one character looks like two characters. In terms of organizational arrangements, there is also a huge gap in density. In terms of writing, it also went against the traditional writing speed of the Wei and Jin Dynasties, which was "hurried but not as steady as cursive script", and adopted a bold and freehand lyrical form.
The writing style of this piece of cursive script is unrestrained and uninhibited, like lightning and thunder, traveling thousands of miles in a flash, but still staying within the rules. The writing is ups and downs, intertwined with movement and stillness, and the paper is filled with clouds of smoke. It is truly the pinnacle of cursive writing. Dong Qichang commented: "It has the potential of falling from a cliff, and of torrential rain and whirlwind."
For "Four Collections of Ancient Poems", Zhang Xu himself did not have a book title. He said that it was Zhang Xu's work based on Dong Qichang's identification, and many descendants This is said, but it is also quite controversial.